ebola

The ebola virus is one of the most feared diseases in the entire world. It belongs to a family of negative-stranded RNA viruses known as Filoviridae. This virus has presented numerous challenges to the medical and scientific communities, because it is very difficult to study live specimens. It is extremely hard to treat as it is unclear how it originates, and they haven't many ideas as to what an effective treatment would be. (Research is on-going, of course.) There are several strains, three which can have a human host, one that is strictly found in animals, and others that haven't been pin-pointed yet. Primates seem to be a likely suspect, as far as the origin goes.

There haven't been any cases documented in the U.S. or Canada, aside from an incident where a group of monkeys infected with a strain of ebola were shipped from Europe to the United States. This isolated incident didn't lead to any human infections, but it still seems pretty frightening that it happened at all. (Note: Apparently, there was a human infection. My apologies - reasearch I had conducted at the time this node was written did not indicate that was the case.) Places ebola outbreaks have occurred include: Zaire, the Tai Forest, Sudan, Reston, and in some other isolated communities in Africa. It is suspected that this can be partly contributed to living conditions, and the high population of primates.

The patient generally dies within a two week period after contracting ebola, and the cause of death is normally attributed to extreme loss of blood, dehydration, and quite often, shock. The only semi-sucessful treatments have included injecting the person with the blood from someone who has recovered from ebola, in addition to repeated blood transfusions to combat blood loss as well as continuous rehydration. All of the treatments have had mixed results, so it is unclear as to their effectiveness. The main areas targetted by the disease are the liver, kidneys, spleen, and basically all of the major internal organs.

The disease is so highly contagious, inflicted persons must be kept in isolation. The disease is spread mainly through bodily fluids, but research and experience in affected areas indicate the disease may very well be airborne.

What I'm saying here is, pray that you never get this, or you'll just be, well, totally f#@$ed.

Actually, during the Ebola Reston crisis, four human beings did contract the virus. Three developed minor headaches and one person had a heart attack (he died some hours after the cardiac arrest, which is believed to have been brought on by the virus and, therefore, gives him the distinct- and posthumous- honor of being the first US victim of Ebola on American soil, this honor subdued by the fact that he did not expire from classic ebola symptoms).

The Centers for Disease Control CDC and United States Army Medical Research Institue of Infectious Diseases (USAMRIID) both worked together to track down the origin of Ebola Reston, which was suspected to be a filovirus (airborne bug). Of particular note is the rumor that the incident at Reston was the inspiration for the movie "Outbreak."

Ebola Reston had a kill ratio of 90%, like the other strains, but appeared to burn through the monkey stock in a matter of days rather than weeks. The incredibly fast motion of Ebola Reston makes it the most lethal strain so far. That four humans contracted it makes it cross-species capable, which scares the living hell out of most medical facilities, but the capacity to jump species is underscored by the apparent fact that Ebola Reston's symptoms in the human species are atypical of most other Ebola strains.

Source: The Hot Zone, by Richard Preston (Random House)

The Ebola virus is named after a river in the Democratic Republic of the Congo, (formerly Zaire) where the virus was first recognized. The Ebola virus causes an often-fatal hemorrhagic fever in humans and primates. Three of the four species of Ebola have caused disease in humans: Ebola-Zaire, Ebola-Sudan, and Ebola-Ivory Coast. Ebola-Reston causes disease in non-human primates.

Structure of the virus

Ebola is one of two members of a family of RNA viruses called the Filoviridae. Filovirus virions appear in several shapes: long, sometimes branched filaments, as well as shorter filaments shaped like a "6," a "U," or a circle. The virus filaments may measure up to 14,000 nanometers in length, with a uniform diameter of 80 nanometers. They are enveloped in a fatty membrane. Each virion contains one molecule of RNA. New viruses are created by budding from the surface of their hosts' cells; however, filovirus replication is not fully understood.

History of the virus

The first filovirus was discovered in 1967, when laboratory workers in Germany and Yugoslavia who were handling tissues from green monkeys, developed hemorrhagic fever. The virus was named after Marburg, Germany, the site of one outbreak. In 1975, Marburg reemerged in a traveler exposed in Zimbabwe became ill in Johannesburg, South Africa.

Ebola was first identified in 1976, when two outbreaks of Ebola HF occurred in Zaire and Sudan. These outbreaks were two different species of virus, named after the nations in which they were discovered. Both were highly lethal- 50% of Sudanese cases and 90% of the Zairian cases resulted in deaths.

In 1989, Ebola-Reston was discovered in an outbreak in a primate quarantine facility in the United States, but did not cause illness in infected humans. Ivory Coast was discovered in an outbreak in 1994.

Since its discovery, large outbreaks have occurred in Zaire and Sudan in 1976, again in Sudan in 1979, in Gabon in 1994, again in Zaire in 1996, and in Uganda in 2000 and 2001. All of these outbreaks resulted in fatality percentages of 50-88%.

Symptoms of Ebola hemorrhagic fever

Within a few days of infection, most patients suffer high fever, headache, muscle ache, stomach pain, fatigue, and diarrhea. Other patients may experience sore throat, hiccups, rash, red and itchy eyes, vomiting blood, and bloody diarrhea.

Within a week of infection, most patients have begun experiencing chest pain, shock, and eventually death. Other patients experience blindness and bleeding. Massive internal and external bleeding is an effect of the disease.

Medical treatment and immunization

There is no treatment for Ebola. Currently, patients receive supportive therapy. Standard therapy includes balancing the patients fluids, maintaining oxygen status and blood pressure, and treating them from complicating infections. During one outbreak, eight patients were given the blood of individuals who had been infected and recovered. Seven of the eight survived, but the small size of the sample and the young age of the patients, which predisposed them to recovery, make this inconclusive. There is currently no immunization for Ebola.

Natural reservoir

The habitat of Ebola is unknown. Researchers believe the disease is animal-borne. The virus is only known to be native to Africa. Bats and monkeys are suspected to be carriers of the disease. It seems that between outbreaks, the disease retreats into the jungles of Africa.

Spread of Ebola

Human infection is hypothesized to result from contact with an infected animal. People can be exposed to the Ebola virus through contact with the blood or secretions of an infected individual. The virus is often spread through family and friends. People can often be exposed through contact with contaminated objects, such as needles.

Transmission in health-care settings is common with Ebola. In African hospitals, patients are often cared for without use of masks, gowns, or gloves, and transmission occurs when patients are cared for without the use of these protections. Airborne transmission has been documented with Ebola-Reston in primates, but has not been documented among humans.

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Works cited

Centers for Disease Control. "Disease Information: Fact Sheets: Ebola Hemorrhagic Fever." (http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/ebola.htm)

Centers for Disease Control. "Disease Information: Fact Sheets: Ebola: Case Table." (http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/ebotabl.htm)

Centers for Disease Control. "Disease Information: Filoviruses." (http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/filoviruses.htm)

Centers for Disease Control. "Reemergence of Ebola Virus in Africa." (http://www.cdc.gov/ncidod/EID/vol1no3/sanchez/htm)

Ebola hemorrhagic fever is the third deadliest infectious disease known, after HIV, which causes AIDS (acquired immunodeficiency syndrome), and rabies, which has an effective vaccine. Though, if I had to choose between any of these three diseases, this would be first crossed off the list. You will soon see why.

The Disease Itself

The onset of the disease is quite rapid: Symptoms can occur within two to 21 days after infection, althought sometimes victims can be asymptomatic(Ebola Reston). Once symptoms begin to show, death can occur within days or after about a week at most. The first symptom is usually a headache, followed by steady fever. The virus causes patterns of clots and hemorrhages. The clots form throughout the body, filling capillaries and shutting off blood to parts of the internal organs, especially to the brain and liver (concidentally, your most vital organs.) This causes the affected organs to begin to die, and decay. You die from the inside out.

And as if it can't get worse, blood begins to leak through the capillaries and into the tissues, much like blood pools in a corpse, though by this point the blood will not clot, and the victim is still quite alive. The connective tissues lose their elastic nature and become not unlike thick soup. The body's internal cavities fill with blood, and blood leaks from all orifices and through the skin, which, engorged with fluid, becomes easily torn, leading to more bleeding. As the disease progresses, victims develop a fixed and expressionless face, probably as a result of bleeding within the brain. (stroke)

Consequences of Infection

Death comes from excessive blood loss and shock. The Ebola virus saturates all of the fluids flowing from the body, which flow quite enthusiastically and unrestrained, making it highly contact-infectious. Contaminated blood, mucus and even semen have been identified as routes for infection. There is evidence of a possible respiratory route of transmission, but only between non-human primates. Handling infected animals, humans or organs, as well as hypodermic needles having come into contact with a victim, are all infectious.

Protection

There is no vaccine against the Ebola virus, nor is there a cure once the disease has been contracted. The nature of the disease dictates a curb on scientific research, the results of which lead us to know very little of this horrifying disease.

In the End

Bloody, mushy death occurs in up to 90% of cases, making outbreaks anywhere in the world very serious indeed. Such epidemics have occured in Zaire, the Ivory Coast, and the Sudan in Africa, believed to be the melting pot of the virus. Somewhat recently (a little more than a decade) ago, an outbreak occured on American soil with one known human casualty.

Lastly, For the Morbidly Curious

You can find videos of ebola patients on the internet, if you're really that masochistic.